A 3-D finite element analysis on the mandibular movement pattern and stress distribution during symphyseal widening / 대한치과교정학회지

ABSTRACT

OBJECTIVE: The objective of this study was to evaluate the displacement pattern and the stress distribution of the finite element model 3-D visualization during symphyseal widening according to the osteotomy position, osteotomy type, and distraction device. METHODS: The kinds of distraction devices used were tooth-borne type, hybrid type, bone-borne type and tooth-borne type 30degrees angulated, and the kinds of osteotomy design were vertical osteotomy line between the central incisors and step osteotomy line through the symphysis. RESULTS: All reference points of the mandible including the condyles were displaced laterally irrespective of the osteotomy position, osteotomy method and distraction device. The anteroposterior or vertical displacements showed small differences between the groups. The widening pattern of the osteotomy line in the tooth-borne type of device was v shaped, and that of bone-borne type was a reverse v shape. However, the pattern in the hybrid type was parallel. The lateral displacement of the mandibular angle by the bone-borne device was more remarkable than the other types of devices. The displacement by the 30degrees angulated tooth-borne type was different between the left and right sides in both the transverse and anteroposterior aspects. CONCLUSION: The design of the distraction devices and osteotomy line can influence the displacement pattern and the stress distribution during mandibular symphyseal distraction osteogenesis procedures.